Merge pull request #5498 from jreback/msgpack_perf

PERF: msgpack encoding changes to use to/from string for speed boosts

Author: jreback

pandas/core/common.py

@@ -1871,8 +1871,12 @@ def _asarray_tuplesafe(values, dtype=None):
         else:
             # Making a 1D array that safely contains tuples is a bit tricky
             # in numpy, leading to the following
-            result = np.empty(len(values), dtype=object)
-            result[:] = values
+            try:
+                result = np.empty(len(values), dtype=object)
+                result[:] = values
+            except (ValueError):
+                # we have a list-of-list
+                result[:] = [ tuple(x) for x in values ]
 
     return result
 

pandas/core/generic.py

@@ -851,8 +851,8 @@ def to_msgpack(self, path_or_buf, **kwargs):
 
         Parameters
         ----------
-        path : string File path
-        args : an object or objects to serialize
+        path : string File path, buffer-like, or None
+           if None, return generated string
         append : boolean whether to append to an existing msgpack
                 (default is False)
         compress : type of compressor (zlib or blosc), default to None (no compression)